Finally found the cause of the error, environment variable ORA_NLS10 not set even though successfully completed the $ORACLE_HOME/nls/data/old/cr9idata.pl executed to create $ORACLE_HOME/nls/data/9idata from upgrade notes

This load was initiated at oacore.web.html.jsp8892557:0.0.0 using the loadClass() method.

The missing class is not available from any code-source or loader in the system.at oracle.jsp.runtimev2.JspPageTable.service(JspPageTable.java:387) at oracle.jsp.runtimev2.JspServlet.internalService(JspServlet.java:478) at oracle.jsp.runtimev2.JspServlet.service(JspServlet.java:401) at javax.servlet.http.HttpServlet.service(HttpServlet.java:856) at com.evermind[Oracle Containers for J2EE 10g (10.1.3.0.0) ].server.http.ResourceFilterChain.doFilter(ResourceFilterChain.java:64) at oracle.apps.jtf.base.session.ReleaseResFilter.doFilter(ReleaseResFilter.java:26) at com.evermind[Oracle Containers for J2EE 10g (10.1.3.0.0) ].server.http.EvermindFilterChain.doFilter(EvermindFilterChain.java:15) at oracle.apps.fnd.security.AppsServletFilter.doFilter(AppsServletFilter.java:318) at com.evermind[Oracle Containers for J2EE 10g (10.1.3.0.0) ].server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:627) at com.evermind[Oracle Containers for J2EE 10g (10.1.3.0.0) ].server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:376) at com.evermind[Oracle Containers for J2EE 10g (10.1.3.0.0) ].server.http.HttpRequestHandler.doProcessRequest(HttpRequestHandler.java:870) at com.evermind[Oracle Containers for J2EE 10g (10.1.3.0.0) ].server.http.HttpRequestHandler.processRequest(HttpRequestHandler.java:451) at com.evermind[Oracle Containers for J2EE 10g (10.1.3.0.0) ].server.http.AJPRequestHandler.run(AJPRequestHandler.java:299) at com.evermind[Oracle Containers for J2EE 10g (10.1.3.0.0) ].server.http.AJPRequestHandler.run(AJPRequestHandler.java:187) at oracle.oc4j.network.ServerSocketReadHandler$SafeRunnable.run(ServerSocketReadHandler.java:260) at oracle.oc4j.network.ServerSocketAcceptHandler.procClientSocket(ServerSocketAcceptHandler.java:230) at oracle.oc4j.network.ServerSocketAcceptHandler.access$800(ServerSocketAcceptHandler.java:33) at oracle.oc4j.network.ServerSocketAcceptHandler$AcceptHandlerHorse.run(ServerSocketAcceptHandler.java:831) at com.evermind[Oracle Containers for J2EE 10g (10.1.3.0.0) ].util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor.java:303) at java.lang.Thread.run(Thread.java:595)

To solve this issue, there are two ways
1. Set the JSP compilation to Automatic
2. Recompile the JSP manually

How to set the JSP compilation to Automatic
Use the vi editor to edit the $CONTEXT_NAME.xml context file used by AutoConfig and change the value for "s_jsp_main_mode" from "justrun" to "recompile" (without the double quotes)

Backup the context file before editing it.

Run Autoconfig to propagate the changes to the configuration files.

Verify that now the
$INST_TOP/ora/10.1.3/j2ee/oacore/application-deployments/oacore/html/orion-web.xml has

Restart the Middle Tier services and access the applications to load JSP's which will cause them to be recompiled on the run.

After successfully accessing the applications, use the vi editor to edit the $CONTEXT_NAME.xml context file used by AutoConfig and revert the value for "s_jsp_main_mode" to "justrun" (without the double quotes) in order not to hamper the performance of your system.

Run AutoConfig to propagate the changes.

How to recompile the JSP manually

You can always use the this option to compile JSP's manually at any time.
Connect application tier using applmgr user and source the environment by running the script: